94 Ranger with 4.0L fuel mileage down to 12.75mpg...

First tank was 16mpg. Second tank 12.75mpg. No I dont drive whole lot. This is mostly my grocery getter for winter thanks to its high ground clearance.

Looking online and they said check the oxygen sensors. A 94 only has two. I did. One was light tan like a spark plug would look in an engine where fuel ratio is correct. Other was black with fluffy carbon on it. Online they said either bad oxygen sensor or a leaky injector on that bank of cylinders. I replaced both oxygen sensors with new Denso sensors. Found new pair on ebay for $25 shipped each. Good price for Denso. Already learned not to bite on generic sensors just to save $5.

I started it afterwards and it took some time for check engine light to come on compared to before, where it came on immediately, but it did come on. Possibly could be me bypassing the IAC. Or something else. I will try to remember to stop at Autozone next time to town and get a readout of codes. I am just not up to counting little flashing lights. Am curious if this will increase gas mileage. 16mpg in a Ranger is bad enough. 12.75mpg really sucks, I get 13mpg on my old '84 F250 4wd with the 300-6 and a non-computer carburetor. It weighs 6000 pound compared to 4000 pound for Ranger. I used to get 16mpg on my old full size 1960 Chevy Apache with 235-6, granny 4spd, and an eight foot bed. And it wasnt geared for economy. So a smaller truck thats geared for economy and is a computerized modern wonder with similar size engine, cant do any better????? Progress??? Seriously a 4.0L Ranger should do at least 20mpg. The LIMA 2.3L engine would do 25. Think the later DOHC 2.3L would top 30mpg.

Ok, refilled tank yesterday and 13mpg. GRRR.... Been reading and reading online. Finally figured its either the temp sensor that tells computer the coolant temp. Or its the fuel pressure regulator. Went out and looked for the fuel pressure regulator. Found it. BINGO! Some previous owner had disconnected the vacuum line going to it and capped off the vacuum ports on both the regulator and the manifold.

These fuel pressure regulators used to be dealer only part and they charged moon for them, well over $100. Ford redesigned things in late 90s and put regulator in the fuel tank along with the pump. So less and less demand, plus third parties started selling them. Anyway after lot searching, found new one on ebay for $30 shipped. Its on its way. I didnt even test current one, figure current one has ruptured diaphram, so was leaking and some previous owner not feeling like buying a new one, just plugged off the vaccum ports so raw gas wasnt sucked into the manifold. However this meant no pressure regulation so pressure can spike and engine runs rich. REad of many Explorers with this engine from that vintage where fuel mileage would suddenly drop from high teens to 12 to 13mpg and corrected by new pressure regulator. Hey makes perfect sense to me.

This engine is no mileage champ, but no reason in world it shouldnt get 16 to 18 mpg on regular basis. Still nothing to brag about, had heavier V8 vehicles with no computer that did that well.

Like said before if this engine got 35mpg, then I would praise the electronics as a miracle. But when it doesnt do any better than an antique carburetor engine without all the complexity, its just another unnecessary expense to keep it in repair.

I replaced FPR with a $30 new one off ebay. Mileage went down to 10mpg. Somebody suggested the air temp sensor. I pulled it and found it was wet with gasoline. Where no gasoline should be. Yep, dud FPR. Ordered a new Motorcraft one for $60. Also new coolant temp sensor and air temp sensor. Took long drive today. 14mpg. Hey better than 10mpg, but we are still talking mileage more like a full size pickup with a V8.

I will putter with it while longer but think its due for an engine transplant. I dont have emissions inspection here so going to get a carburetor straight six. A chevy no less cause I happen to have one in good shape. It also easier to fit than a ford straight six. I know, put a Ford straight six in the old Ranger. I got 16mpg when this old chevy six was in full size pickup. Think had like 3.73 axle. Should get better mpg with the Rangers 3.27 axle. I even found article of some guy that put progressive 2bbl weber carb on his old chevy straight six and got 18.5mpg with that 3.73 axle.... Sounds like a plan.

Though I did get a fuel pressure tester so will fiddle a little more with the 4.0L. But its gotta get at least 16mpg on regular basis to remain in the truck. Sorry but I could put a stock carburetor chevy 350 in there and probably get 14mpg on long drive!!! Lot more fun to drive too....

Ok, long interlude. Back in May or June 2016, transmission went out on this Ranger. Shifter was flopping around like limp noodle. I managed to get it back up into yard and let it roll back into weeds over summer.

Ok, this is a 4200 pound truck with 4.0L engine and what amounts to same light duty 5spd Ford used on the 4cyl, just different bolt pattern. I found one with low miles for around $500. Rebuilt one costs $800. Pick a part yard ones most likely high mile and not lot better shape than one that failed. All seemed kinda pointless to me.

I got notion of using an old Chevy granny 4spd I had out in yard. Its probably from early 60s. Seriously you have to really try to seriously abuse one of these to kill it, they were one of toughest transmissions ever used in a pickup and even used in 2 ton truck back in the day. Trick is finding a bellhousing to adapt. The Mazda transmissions Ford tended to use in all Rangers had bellhousing as part of the transmission housing. Well there was some kind of $800 custom racing bellhousing for these Ford 4.0L, but nobody had one in stock, you wait until factory makes a batch sometime in indefinite future... And really, $800??? Guilding the lily a bit.

This is a Cologne bolt pattern engine like the older 2.6L, 2.8L, and 2.9L engines used in various Ford products here and Europe from late 60s to 2014 when Ranger production ceased. Well the older stuff pretty rare and expensive. I finally found the late 80s Mitsubishi 5spd used in some Rangers had a separate bellhousing and a round indexing hole. Some guy had one for sale on ebay for $60. I asked him to measure the indexing hole. Only slightly smaller than traditional Chevy bearing retainer. I got it. Turned down the bearing retainer on the SM420 for snug fit on my mini lathe and all it could handle! Luckily the cast iron housing on this SM420 is very strong. Was able to drill holes in bellhousing at reinforced points, on into the transmission housing and threaded the holes in the transmission. Seemed strong enough except the SM420 was designed to hang off the back of a very heavy duty cast iron bellhousing that took all the weight and had transmission mounting areas cast into it. This feeble little engineered aluminum mitsubishi bellhousing not up to that. I used big chunk angle iron and made a rear mount for the SM420.

Ok fall gets here and I install it making custom cross member, lengthen driveshaft, all that kind thing. Drove it around my property a bit at one point, but was noisy, the y-pipe wasnt sealing on the passenger side to exhaust manifold. After lot messing decided the OEM light duty "engineered" flange wasnt holding properly. Got a Walker repair flange and that silenced it. Then had problem with clutch arm hitting the y-pipe. Sliced and diced and rewelded it for umpteenth time. Finally got it so it wouldnt hit though gotta be the weirdest looking clutch arm ever.

The original plastic master cylinder on this Ranger was mounted at a downward angle. I extended out the brake booster with a spacer big enough to let me mount a Wilwood master cylinder in traditional clutch master spot on firewall next to this spacer. Well Ford had designed the clutch pedal in S shape with pivot made to work with the original downward pointing master. Connecting the Wilwood to this pivot made rod bind at one point in its stoke. Figured out I couldnt use the pivot on clutch pedal that original rod used. So had to take clutch pedal out of truck (nightmare part 1), weld on it, then reinstall it (nightmare part 2). Right now pedal to master linkage fine, no binding. But my gosh Ford engineers really dont want you working on anything up under that dash.

But in meantime I had borrowed the Wilwood clone slave from Ranger to use on the F250 when its Wilwood clone slave failed. Seems this brand of clone uses cheapest crappiest rubber parts possible. Or maybe they just set in some warehouse for couple decades. The one that failed on the F250, the dust boot was in shreds, looked like it had been on there 50 years instead of nine months.

The clone slave I borrowed from Ranger of course worked fine as it was brand new. But two weeks later I was under F250 for other reason and noticed the dust boot on this clone slave had come apart at one of the accordion bellows pleats. Dryrotted and failed in two weeks. Jeesh.

Just today when temp got into 40s, I put new non-original dust boot on it. Hopefully that gives it some extra longevity. I have also ordered a genuine Wilwood slave to use on the Ranger. You can get rebuild kit for the genuine Wilwood, basically two o-rings and a new dust boot for $15. The clones tend to use different piston with one o-ring and a cup seal. I finally found company called CNC that sells a clone version, also makes a rebuild kit but wants more for the kit as a brand new complete clone like I bought. I gave $40 each for my clones. The CNC rebuild kit goes for $45 to $55. Kinda funny (and frustrating if you need it)..... as it makes no sense whatsoever to even offer a kit for more than actual complete new unit.

Anyway hoping the genuine Wilwood holds up better. Going to mount it with two heim swivels since genuine Wilwood slave is very sensitive to precise alignment so piston isnt forced where it wears one side of cylinder more than others. The heim swivels let it do straight even pull even if the clutch arm and anchor point arent always in precise alignment.

So get to see both if good quality dust boot lets clone have some longevity and whether the heim joints let the genuine Wilwood have longevity.

Got the Wilwood slave and the heim swivels in mail yesterday. Waiting for nice weather day to install.

Installed and adjusted to where I can shift when I push clutch pedal all way in. But not happy, requires way too much effort. It would be unpleasant to drive it like this in traffic. Much like the F250 was in traffic until I modified its clutch linkage. When I only occasionally used it, was livable. but last summer after tranny self destructed in the Ranger, had to promote F250 to my primary vehicle. I had incentive to improve shifting in traffic by improving clutch linkage. Its much improved and not such a pain to drive in traffic. Devil is always in the details.

I am thinking the clutch arm on Ranger is hitting edge of its exit hole in the bellhousing. Thus trying to use that edge as fulcrum instead of the pivot ball. With the defacto fulcrum futher out, it loses mechanical advantage. Like being the skinny kid on the teeter totter. You need as much mechanical advantage on the lever as possible, much more difficult the farther you slide in towards the center.

Anyway clutch is same 10 inch as it was with original transmission, just a 10 inch Chevy disk instead of a 10 inch Ford disk.... Same Ford pressure plate and flywheel. Shouldnt require anymore pedal effort.

Two ways to deal with it. I can elongate the hole in the bellhousing. Or I can modify the clutch arm so the fork end of clutch arm that engages the release bearing sits further forward than it does now. Probably half inch would do. Course I remove clutch arm, maybe just as well do both.

No real hurry. Do it while its still up on blocks with easy access.

Ok, the clutch arm wasnt coming out without taking loose the y-pipe. That became my least favorite option immediately on discovering that.

Also couldnt get the die grinder nor the dremel in good position to extend the hole. But I could drill holes. I drilled series of small holes side by side and then used long heavy duty screw driver to knock out the chunk of metal. This is some kind of aluminum alloy so not too difficult though did leave bit of a rough edge. Beats taking stuff apart for better access though.

Hooked slave back up. And clutch works much better. I had guessed correctly that clutch arm was hanging up on the bellhousing. And works ok without over tightening the slave cylinder adjustment when its in relaxed position. I also do like having clutch and brake pedals further apart (I hammered out the bend in clutch pedal). On their compact vehicles, Ford always did seem to put the pedals uncomfortably close together. Fine for some delicate little gal with tiny feet, but not pleasant for a full grown male or somebody wearing overshoes or something. Now matter of reassembling dash stuff and emergency brake pedal. I'd say its now ok to drive without constantly worrying about clutch disengaging enough to change gears.

No doubt things will loosen up more as I drive it more.

Well, ran across mention someplace of these early 90s Ranger/Explorer/Aerostar ECMs having swollen/burst capacitors. This was common on desktop pc's at one point. Companies were searching out the cheapest commodity price on capacitors and bit.

So finally pulled the ECM on my Ranger, same one that was in it when I bought it. Turns out the part number translates to 1994 Explorer, federal emissions, with manual transmission. Problem is the 94 Explorers were year ahead of Ranger and had went to sequential injection and used a cam position sensor. My engine set up for batch injection with no cam sensor or EGR way it came from factory. Meaning this thing has been running on some "limp home" mode for all time I've used it. I assume more from no imput from any cam sensor being more important than non existant EGR. No idea whatsoever how it even starts and runs since this computer does sequential injection and my injectors arent wired that way.

But I am getting ahead of myself. At first I though ok, bad ECM, look on ebay and find a $17 one for 94 Explorer with automatic. I live in state without emissions inspection currently, so if it threw a code cause it didnt find automatic transmission lockup or whatever, doesnt matter. I mean its been running with CEL on since I bought it.

So that one arrives and yea, truck again starts and runs, but even rougher than it did with one I pulled.

So figuring things out I look for proper ECM. Yea, used ones on ebay start at $150. Over $200 at parts store. Great so run across a thread on some Ranger/Explorer forum from guy saying the ECM for 3.0L engine will run 4.0L engine fine and dandy despite everybody saying it wont. I just gotta try this. Found another ECM for 92 to 94 Aerostar with 3.0L engine for $23 and it should be here Monday. Its for non-egr system. The 3.0L engines used in Ranger/Aerostar might even went to 95 without EGR. Unfortunately the give away ECM for Taurus with this engine always was EGR.

In mean time I post about this on a Ranger/Explorer forum and they suggest car-part.com to find the correct original ECM for my truck. They even offered phone number for guy that has one for $75 plus shipping. Lot looking and I find one for $35 plus shipping at some junkyard in Utah. If the Aerostar 3.0L ECM doenst work very well, will order that.

Hey I am learning. And if I have to buy the Utah ECM, all three together still significantly cheaper than buying correct one off ebay or at parts store. Slowly but surely I am being dragged kicking and screaming into the electronically controlled automobile age. I know early 90s still pretty far back and still OBD1... Move to OBD2 era and you get the wonders of PATS/VATS security that actually only secured extra profit to dealers for making crazy priced keys. Thieves in modern age just use tow truck or trailer, they dont hotwire ignitions. All this so called security does is make life a nightmare for those getting those last miles out of a vehicle. And ever more complexity with more sensors. And ever more delicate and complex and expensive engines.

Though after all the struggles, despite my having learned a lot, if doing it over again, would just have used the Chevy straight six carburetor engine that would easily bolt upto one of these old granny trannies. I know how to get 18 to 20mpg out of vehicle this size and weight, with Chevy straight six, without a computer or fuel injection. Might even do better considering the axle ratio in Ranger. Those old Chevy pickups usually geared pretty low.

I had some years back put Ford 300 straight six into an 84 Ranger. I know the problems involved. The Chevy straight six would be a much easier fit. Still long engine, but manifolds are on drivers side so no interference with heater box. At least the 250 and smaller versions were narrower than the 300 and the oil pump is on the front passenger side so no notching into the axle cross member. Oh and the oil pan sump is set further back so no modifying the oil pan. Yea I prefer the Ford 300, but the Chevy 230/250 is just much better fit in Ranger/Explorer. Now if I could find a Ford 200/250 "falcon engine" in good shape, that would probably work ok too though would need oil pan from Fox body version, the older ones had front sump. A good condition used Ford 200/250 pretty rare. You could find such an engine, but it would most likely require complete rebuild. The 300 still findable, the fuel injection version made through 1996 and can be converted back to carb pretty easily though if you have the wiring harness, not a real need to do so. Six of one, half dozen of other situation. No real advantage to fuel injection on 300 either, they were long stroke "tractor" engine and carb version properly tuned got just as good mileage as the fuelie version.

Ok, I went down to clusterbox and got the ECM for the 93 Aerostar with the 3.0L and installed it.

Ranger started, ran little odd until I plugged in the idle air control, idle immediately increased to 1000rpm and engine smoothed out, which is about right when cold. I had it off before to keep truck from stalling at hot idle. As truck warmed up, engine ran smoother and smoother. Idle dropped to 500. It did do the hot idle stall at one point, but started right up and didnt stall again.

Anyway, I am going to move the F250 out of way and do some testing with it. Want to see how it acts under load. But frankly its running far smoother than it has anytime I've owned it so I suspect good things during testing. And hopefully thats it, dont have to buy any more ECMs.

CEL on, but would guess thats because this ECM is for an automatic transmission vehicle. There is a way to trick an automatic ECM into thinking automatic still there with couple resistors. Though since I dont have emissions inspection, dont really care.

So that guy posting that one thread was indeed telling truth. A 3.0L ECM can start and run a 4.0L. Now how it drives out on hiway..... still to be determined. But just way it sounded, pretty sure it will do ok.

I took it down the the drive and then the county road and turned around just before chicken house hill. It made noises and smells like anytime you do major changes. Shifted like you would expect an antique transmission that hadnt been used in couple decades. Brought back memories of the old Chevy Apache pickup with this same transmission....

Ranger runs fine. This ECM should do fine. Engine running very smooth. I didnt even think about the engine during test run, just about the transmission. If I actually had working accurate odometer, betting this ECM would get mileage of 16mpg, maybe more.

Still freaks me out a bit how fast granny first gear is with this economy rear axle ratio. First in this transmission is the lowest first gear of all granny four speed transmissions. But with this axle, its just little slower than a normal first gear, doesnt feel like a creeper gear. In the old Chevy, it barely moved when you had it in granny first. Will say its near perfect for getting up my steep driveway. Slower than first in the original Ranger transmission and crawled right on up with no hesitation and no hint of stalling out. Felt lot like the old 72 Courier I had, it was geared so first was slower than normal first would be, so had lot low end umph. Yet I am not going overly fast and bouncing two foot in air on every bump. Nor super slow creeper crawling.

Next test will be when I go get mail again, will take it out on hiway down to the roadside park. That will give me clue how it does on hiway without getting in any traffic. Also how it handles the big chicken house hill. Of course it would crawl up in first, but curious if it can make it up at least in second. I cant remember now what gear I came up CHH hill with in old transmission. Seems like second. Third in this transmission is between second and third in the original transmission. Fourth is same 1:1 ratio in both transmissions. No overdrive needed with this axle ratio.

Update. Good news and bad news. First I drove to town in it. Transmission had odd occasional squeal when cold. Drove on hiway fine and no noise when warmed up. But when I got home, felt heat. The transmission was HOT to the touch. These old heavy duty granny transmissions at most get luke warm after heavy use. Pretty sure there is a bad bearing, thats the squeal. Bearing locked up and spinning on the shaft, rather than balls/rollers turning.

Guess I posted this transmission had set outside for very long time and I found bit rain water and some rust inside it. I cleaned up rust best I could and put in fresh lube, but gambled and didnt disassemble it. Lost my gamble. You can get a rebuild kit, but good chance shaft is worn at this point and either need replacement or expert repair. But I have couple spare transmission. I know one should be good, I had pulled the lid at one point, no water, no rust. Didnt open the other. Never driven a vehicle with one of these three installed, so also possible damage when I aquired them. One is out of pickup that friends ex wrecked when they were married. The other two are $5 bargain at long ago auction when nobody much wanted these. Now they have some popularity with rock crawler Jeep crowd, they like the super low first gear.

So I get to remove and replace transmission again. Oh joy. Be foolish to ignore the squeal and heat and continue driving it this way.

Update. Finally got back to Ranger. Got clutch arm removed and release bearing looked at angle. Ok, pull transmission. Nope, release bearing self destructed in the ten miles it was driven. Apparently left factory with no grease. I bought a NOS American made bearing, this one the old long style that GM used on the old straight six with a particular pressure plate. The existing cast iron clutch arm didnt like the groove this bearing had. I made opening in bellhousing bit bigger and used a later stamped steel clutch arm. Of course it didnt like the exhaust y-pipe and I am tired of cutting and welding arm to try and get around the y-pipe, rather have staight direct pull by slave cylinder. Well had enough of that stupid y-pipe. Order mandrel bent pieces to make make my own from scratch. Moving the cross over part back behind the transmission. The driveshaft is high enough not to be problem. Course this means I delete the catalytic converter. But when I had everything apart after first buying the truck, when I turned converter vertical, the innards just fell out. Truck has 200k mile and this no doubt is original converter. No emissions inspection in this state so not going to worry.

Now getting universal exhaust parts anymore not particularly cheap. Though AdvanceAutoParts online had Nickson brand reasonable with free shipping. Even found a discount code that got me another 25% off. Works for me. I could just angle cut 2" EMT electric conduit and weld and make my own angles but the mandrel bent provides better exhaust flow I think. Not that it matters, nothing is going to make this an economy vehicle.

Anyway I am thinking now that the squeals that seemed internal to transmission were death screams of that dry release bearing. Though still the consideration of the heat build up. Anyway going to try this transmission again with new release bearing. It wasnt absolutely horrible to pull transmission back enough to put in bearing, that HF transmission jack works nice for this. I am too old to bench press a SM420 transmission.... Not sure why I didnt just make a custom y-pipe before. Guess I wanted the catalytic converter to be there in case I ever did need to replace it and make it functional.

All together yesterday. Still up on blocks, but started it. With clutch pedal pushed, easy to shift gears. Effort to push pedal moderate, less than before probably due to better clutch arm geometry. Redesigning exhaust y-pipe from scratch made life lot easier. No need for twisty curvy clutch arms putting weird stresses on anything. And the long 1 7/8 inch Chevy release bearing definitely way to go. The Mitsubishi bellhousing I used is inch or so deeper than standard Chevy bellhousing. That longer release bearing makes up the difference.

My AWOL neighbor that came to me three years ago to fix driveway, then disappeared off face of planet, showed up the other night saying he is finally ready and found dozer guy who should be here this week. Supposed to be guy that specializes in driveways and knows how to prevent the huge ruts washing into them. Last guy I went in with former neighbor to hire knew what he was doing. But former neighbor cheaped out and had dozer guy stop as his property. Well that just meant water came down middle of drive from above his property and washed a big rut at the curve. Jeesh, nobody mentioned stupid, I'd paid the dozer guy little extra to finish the job properly, wouldnt take that much time.

So waiting to try Ranger until that happens, no reason to fight my steep rutted drive with 2wd needlessly. No point to prove. And I did warn him that gravel washes off the drive, even the good kind that compacts well, so isnt really worth the money. But he is paying for it up to his place. Good for him, all gotta learn I guess. But be nice for a year or so, especially in winter or when its really muddy.

Okay, driveway is fixed and graveled. Took Ranger for a drive. Stalled every time I slowed down. GRRRR! It even got to stalling when parked idling in yard, once engine was warmed up. But one little tidbit of information. If I unplugged the TPS, it would run stinkin rich, with dark smoke puffing out tailpipe, somewhat rough idle, but it wouldnt stall. So a too lean idle mixture!!!!!

So posted on Explorer forum and on another forum in the shop section. Specified problem. Got the usual advice. Thing is just about all usual suspects had either been tested or replaced. I was getting ready to bite the bullet and take apart manifolds and fuel rail and replace all gaskets and seals.

One guy however suggested screwing in the throttle stop to increase idle speed to where it wouldnt stall. Thought about that a little, seems intuitive, until one considers that the throttle valve is connected to the TPS. So computer is getting TPS reading and reading from MAF about amount air and the other usual stuff. So not as simple as upping idle speed on a carburetor.

The TPS tested ok with voltmeter. But I wondered what would happen if it was moved a bit one direction or other. It isnt made to be adjusted but you can remove screws, turn it a bit and hold it. Well still stalled, but interesting how much just tiny change in position with everything else constant changed how engine ran.... Reminded me a bit of advancing, retarding distributor in a carb car. Ok throttle connected to TPS, so how does throttle stop affect things? This is one of those things only mentioned to tell you not to do it as "it may effect emissions". Nothing about what it would actually do.

Anyway I turned it in a bit like that one poster had suggested thus holding throttle valve a bit more open. It immediately stalled. Ok, how about other direction? Turned it out several turns and engine at first slowed speed a bit, but then regained speed and stabilized at 700rpm. I let it idle for 15 minutes or so. Temp gauge had needle in middle of NORMAL. But no stall! Wow. Apparently throttle stop doesnt change engine idle speed so much as it changes idle mixture (by how it affects computer). Like mixture screw on a carburetor. I assume some previous owner did the adjusting. There really isnt any clue unless you see it after its first done when threads on small section of screw are clean and bright.

Today I took it for test drive. No stalling and seemed to have a wee bit more power.

I also felt the side of the transmission when I got home. Warm but not hot and worrisome like in past.

So is this 4.0L plus SM420 a match made in heaven. Eh, probably not anything to brag about, other than the challenge of making it work and fact this transmission is nearly indestructible. But Ranger is now drivable and will do what I need it to do. And that was the whole idea in first place. I learned something new and that is priceless. If I werent retired with all time in world for this sort of tinkering, this wouldnt been good solution. Re-engineering things takes time and resources to do it over and over until you work out all bugs. If I needed something reliable to get to work every day, then just pony up $2500 for something working out of the box. Or at most just replace drivetrain with an older complete drivetrain. An engine and transmission that bolt up without adaptations.

Ironically now that driveway is nice again, I could get Festiva going and drive it. Only reason I stopped driving it was the driveway in rough condition was beating it to a pulp. Festiva is truly a great little grocery getter in traffic. Not great for long trips. This Ranger is heavy enough and roomy enough it would be ok on longer trip. Its basically an Explorer with a box bed.

It does drive ok now. Except my gosh the exhaust noise gets on my nerves. I was thinking it was my homemade y-pipe not sealing to manifolds well. But that didnt seem right, its ok at idle and only noisy on acceleration, classic sign of a pooped out muffler. Listening at the tail pipe and its loud so not leak, muffler just isnt doing its job. So in process of replacing the muffler. I think this is original muffler factory installed 180k miles ago. Funny looking thing with ridges on its sides.

I found an old long round offset muffler, not sure where it came from, was setting in one of my junk cars. Probably got it with a pile o'crap at some auction or something. Got late start today, but cut off existing muffler and will get out the mig and weld this one in.

Made me think back, dont believe this Ranger ever was whisper quiet since I owned it. And pretty sure me removing the catalytic converter to make room for custom y-pipe that gives room for external clutch arm, showed up weakness of this muffler. Converter was acting as resonator or pre-muffler or whatever.

I did lot googling. Oddly most people looking for mufflers want a louder one. Kids I guess. Anybody has to drive longer distances and that noise gets tiring quickly. But seems Walker FX Sound model mufflers are way to go. Reviews on Amazon for the one for Ranger were complaining it was too quiet.... Sounds like one I would want if this old long round muffler doesnt quiet the Ranger.

Well the old long round muffler I found is on, though I need to install tailpipe and do some other welding to make exhaust system more solid and robust. Anyway started truck. Its ok and much better than it was. Not whisper quiet, but not going to attract attention nor be super annoying to me driving down the road. I guess you would say this long muffler is about like the original muffler in combination with the catalytic converter.

Ok, once engine warm from driving significant distance, exhaust is LOUD anytime I accelerate. Not fun. And check engine light on.

So I first hunt up my OBD1 code scanner. Replace the dead AA batteries (has it been that long since I used it...). Get odd code 70, ECM failed. What it means is the data connection between scanner and ECM not recognized.

Reread the owners manual for the scanner. Okay dokie, my brain failed, not doing it right. Warm up truck and rescan. Get two codes for MAF outside limits. And one for faulty evaporative canister. Thats it. The MAF tests ok with voltmeter so not sure why getting that. Guess I just live with the evaporative canister, that bugger be expensive just to get rid of the code.

And I dig out that original muffler I cut off and replaced. Pipe on one end of it fit into the tailpipe. Wow, does make a significant difference in noise. So guess I splice it back onto Ranger in front of the current muffler. Least now I wont feel mortified as I accelerate up a small incline on hiway and sounds like I am running straight pipes and showing off like some high schooler.

I found a cheap ECM for 93 Explorer (same engine) with Federal emissions and manual transmission. Its batch injection like my 94 Ranger. 94 Explorer is sequential injection.

I get it today, notice its not the number ECM I ordered, its for an automatic 93 Explorer. Least its for Federal emissions, really suck if it was California. Few choice words then decide to see what it does and pop it in. Ranger starts right up, but high idle and little rough. I adjust throttle stop in a bit. Smooths out but lowest hot idle I can make it do is 900rpm. CEL goes out and stays out. Take it for a drive. More power, revs super easy, quieter on acceleration.

Truly only annoyance is overly fast idle and its slow to fall to idle when I take my foot off the gas. I assume its cause it was designed so automatic tranmission engine wouldnt stall out.

Weird no CEL as it should be bitching about no signal from automatic transmission and that purge valve is rusted solid. Thrilled though that the MAF codes disappeared. Saved myself $80 for a new MAF.

I am still PO'd they sent one for an automatic Explorer instead of the one for manual Explorer I ordered. But hey if it runs ok with no CEL then who am I to complain. They sold ECM as a paper weight, said it had set on shelf for years and they werent guaranteeing it. If it works great, if not then its a paper weight. Probably only cause its EEC-IV system and not OBD2. Pretty sure the more picky OBD2 ECM would bitch a lot. Next trick is seeing what mpg is. With improvement in power, I would assume probably get at least 15-16mpg on hiway. Nothing to brag about but beats 11mpg by lot. Six cylinder in a 4200 pound truck, yea 16mpg probably about right. Its what that old 1960 Chevy Apache half ton got with 235-6 and same SM420 transmission. So much for progress with all the computers and electronics. Yea in my test drive would say that old 235 about same power as the 4.0L, the 235 may had more torque down low just off idle. Sure the Chevy had numerically higher rear end ratio. Ranger has that economy 3.26 ratio. I would guess the Chevy was up around 3.80.

I remember reading that Mustang thread about restricting IAC hole to get idle down. Maybe not worth it. Idling at 900rpm isnt too horrible. Least I know its unlikely to stall out....

Ok, more problems. Started with bad hesitation and rough idle. Even stall starting out with engine under load. Finally wouldnt start.

Did ECM give out? Looking and noticed raggety rubber seal where air intake tube attaches to throttle body. Took it loose and yep, it had pretty well disintegrated. Other rubber seal on MAF end not good either. You by way cant buy just the seals, only tube assembly with seals for a mere $150 to $200. Last of these used in 1994 so unlikely to find good one in junkyard. That pricing on new one be funny for whats basically a plastic tube, if it was somebody else having a need for it. Not so funny when I need one.

Duck taped it and engine started right up, back to way it was. But that not hold for long. So pulled whole tube assembly to take look and see if I could adapt something.

Shock and surprise there were holes worn in bottom of the hard plastic tube. Some genius had designed the tube with a couple accordion pleat areas near ends of tube. Pointless since this is a hard plastic with no give, but it looks pretty I guess. But the edges of the accordion pleats can wear from rubbing and bouncing around over the miles and other than duct tape arent really repairable.

The end of tube near the throttle body so badly worn, I cut away whole accordion pleat area on that end. Left bit of irregular hole but with some experimenting found a 3.25" OD cat food can would tightly fit in hole. Plastic had just enough give to allow this. CAn too short and too light gauge to be useful. And thats an odd size for generic tubing. But found some aluminum tubing, one foot of it for $24 on ebay. Grrrr... but seemed best option. And it also fits in other end minus rubber seal. Now I find there are various sizes of generic Chinese silicone connectors on ebay, sold for "turbo intercooler" but look like good way to go for my air intake tube.

So waiting on that aluminum tube, and two silicone connectors. One going from ID 3.25 to 3 inch on the MAF end and ID 3.25 to 2.75 inch on throttle body end. Should work. Cost me around $36 total for my generic repair parts. Well add couple new hose clamps bought locally to that amount. Yea sounds crazy until one figures cost of any other alternative. I also plan on duct taping heck out of areas where tube was rubbing holes. Let it rub and wear the duct tape rather than the tube or connectors. Some strips of old inner tube might even wear better....

Oh and as far as using something like PVC pipe and fittings. The way Ford routed the OEM tube makes this maybe kinda difficult unless one uses smaller diameter pipe. The OEM tube has a flattened section, round generic pipe might and probably would cause problems with hood closing properly. Or force it down into the fan or belt. Ford only used this particular tube from 1991 to 1994. In 95 they changed to plastic intake manifold with throttle body in different place, and rerouted the air intake.

Oh also did a code scan when hesitation problem happened. Got a lean code. Also three codes pertaining to the missing automatic transmission. They apparently are secondary and dont trigger the CEL on the dash, but do leave codes.

No emission inspection in my state so doesnt bother me, but assume anybody in a state with inspections would be forced to buy ECM for a manual transmission, rare and expensive as those tend to be.

Oh another thing, the radiator on Ranger cooled fine, but weeped antifreezer around seams where plastic met the aluminum.

I ordered radiator from Rockauto.com. Put it on yesterday. Needed two little clips at bottom of radiator to hold bottom of the fan shroud. Dang if I didnt put hole in one of tubes getting one of clips on. My fault so cant bitch too much. Took it off and crimped tube where hole was and sealed with epoxy. Should hold.

Cant believe how fragile these modern aluminum radiators are. But guess the old copper/brass radiators not greatly more robust. The clip probably could been better designed or some warning about installing the clips.

Ok, finally got my pieces. And got to looking around for way to actually glue hard plastic. Seems to be popular fix for plastic radiators, using super glue plus baking soda. Ok picked up fresh box baking soda on last shopping trip and ordered the super economy bundle of super glue off Amazon.

So first test of how this worked to seal accordion pleat on MAF side. Little clumsy with it, would do little different if doing again. But amazingly it worked and held together as I flexed the accordion! I am able to test it cause the rubber on MAF end though not great condition, is still intact and will seal.



Then since I had already cut off the accordion on the other side, inserted short length of 3.25" aluminum tube into the hole and glued/sealed it.



And pic of it installed in Ranger. I did use hose clamps on the red silicone connector, just took pic before I put them on.



No idea how long this repair will hold, but some people using this on youtube seem to think it will last indefinitely. The baking soda not only cures the super glue almost immediately, it cures it to a VERY hard mass. And latches onto plastic like nothing I have seen.

Wow what a difference when I started up the Ranger. No hesitation or rough idle.

Yep, a repaired intake air tube made ECM throw code that TPS high out of range. So had to once again reset the throttle stop. This time searched and seems on this generation OHV engines Ford wants you to warm up engine, then either block or unplug the IAC. Set throttle stop to 500rpm. Wow I had to unscrew stop 4 full turns to get it down to 500rpm. But amazingly it idled perfectly fine like that. I had figured it might barely stay running. I then plugged in the IAC and idle went up to 700rpm like its supposed to. Engine seems more responsive. Havent driven it but would guess the TPS code is gone.

Today put front of Ranger up on blocks and crawled under. Clamps holding y-pipe to drivers side manifold were loose. I tightened them and got rid of annoying exhaust leak. Not new luxury car quiet but as quiet as any old pickup with reasonably tight exhaust system.

I then changed out fuel filter. Couldnt remember if I had done that back when I bought it or not. I hadnt. Cause I would remembered if I got gasoline bath like I did today. Ford simply doesnt like mechanics, especially shade tree mechanics. They had that filter boxed in frame rail and hog tied with a rusty hose clamp. Really hard getting hand up in there to work on it. But its done. I blew through old one and it had noticable resistance. I take it hadnt been changed for a while. Not a favorite task of owners, nor do they want to pay crazy price to some shop until they absolutely have to.

Now important stuff on Ranger is to check lube level in rear axle and the transmission. Both show signs of leaking. I ordered new seals for the rear axle, but could just be vent hose blocked by mud daubber or something. I had replaced seals in transmission, but transmission is OLD and set out in weeds for couple decades so.... Not like I am going to drive cross country in Ranger, so just check fluid levels once in a while. Plus I am finally getting close to where Ranger is seriously reliable. I dont think the previous owner even used it as daily driver. Just to haul stuff as needed.

Yep mud dauber had blocked axle vent hose. Axle down more than half quart. Transmission fine. Took it out for a drive. Ok. Noticed more transmission noise. The old SM420 was just a noisy transmission, designed for medium duty trucks back in 1940s. So what might be startling in modern manual transmission, nothing to worry on the SM420 especially in a light duty truck.

Anyway readjusting the throttle stop eliminated the CEL light. it drives pretty good. Actually pretty good power when you get rpm up. Just I am so used to the old 300-6 where it peaks on torque at 1800rpm. With this engine I am lugging it. Max torque somewhere like 2800rpm. I still much prefer the 300-6. Though this OHV 4.0L has developed a rep for very good longevity. I have great respect for longevity in an engine, especially a mechanically simple one. Its usually transmission or other things that actually wear out on vehicles with this engine. Gets to where it isnt worth putting money in it despite engine still running ok. The engine with regular maintenance can go 400k to 500k miles before rebuild. Thats impressive for any gasoline engine and some light duty diesels.

Now if it can just get mileage up to at least 15mpg. I think it all depends on getting right signals to the ECM so it can calculate correct fuel and timing. Air leaks can create havoc. Think however I have it finally set good as it is going to get. So just wait and see after running another tank gas through it. If mileage still sucks just live with it I guess, not like I drive that many miles anymore. Cant think of anything else I can do for it. Just fact that it has stable smooth idle at 500rpm (IAC blocked) says I probably have air leaks fixed and everything is probably working as it should.

Sure has been interesting adventure. And I have learned a lot. Course never would bought it if I had known it needed so much tinkering beyond just replacing clutch. Whole idea of it was to keep me from having to pull engine on the old 84 Ranger to fix oil pan. LOL. That would been simple compared to what I have done to this. By way think I found my answer on sealing that oil pan if I should desire. That super glue plus baking soda works on any non porous surface. Might even be able to seal it without pulling engine... though better to pull it, remove oil pan and clean it, then seal it inside and out. Though bet gas tank is mess by now with gas left in it for years, so would have to be replaced.

Last trip to clusterbox, it drives quite nice. But on way back to house CEL came on. This time complaining one bank cylinders running lean. Its running good so not going to worry too much unless it still getting crappy gas mileage. I drive so few miles anymore, still probably be while until I can check fuel mileage.